Drop-Shock Stability of a Thin Shallow Arch Considering the Effects of Variations in Shape

Thin-walled structures can be sensitive to buckling: that is loss of stability under loading. In order to derive design guides for such structures under dynamic loading, a group of thin shallow arches subjected to a half-sine drop-shock pulse is examined. All arches have the same principle dimensions such as width, height and cross-sectional area but differ in shape. Using numerical means and a multi-degree-of-freedom semi-analytical model, both a quasi-static and a non linear transient dynamical analysis are performed. The influence of various parameters, such as pulse duration, dampening and, especially, the arch shape is illustrated. Moreover, results are validated with finite element results. The main results are firstly that the critical drop-shock level can be significantly increased by optimizing the arch shpade and secondly, a small geometric imperfection decreases the critical drop shock level in a much less fatal manner under dynamic loading as predicted from the quasi-static analysis.